It is already known that by rapidly supplying gas to a bag or balloon in the event of a collision, it is possible to inflate the bag to form an inflated buffer structure filled with gas which structure serves as shock-absorbing protection for a passenger in the vehicle. Since, particularly in the case of front-seat passengers, bags are required which when inflated are extremely large and the time for inflation must be extremely short, usually of the order of a few hundredths of a second, extremely high gas speeds are required to effect this inflation. This has in turn caused considerable problems such as the load noise occurring during rapid inflation. Furthermore, the overpressure occurring in a closed car when one or more of these protection means is rapidly inflated may damage the hearing organs of the passengers and cause permanent injury.
Arrangements exist which are aimed at avoiding the drawbacks involved with such conventional protective devices. For instance, it has been suggested that the protective arrangements be inflated by supplying compressed gas to a system of channels having a limited volume, said channels extending along the walls of the protective bag so that the folded bag can be made to expand rapidly while supplying rather limited quantities of compressed gas. At the same time, the ambient air in the inside of the car serves to fill the inside of the expanding bag, thus avoiding the drawbacks of the high gas speeds as well as overpressure inside the car.